XXII. BIOCHEMICKÝ ZJAZD - Jesseniova lekárska fakulta

Lectures
rEGULaTION of aurICIN BIOSYNTHESIS IN
StrePTomyces aureofaCIens CCM 3239
Ján Kormanec, Renáta Nováková, Ľubica Fecková, Peter Kutaš and Alena Reháková
Institute of Molecular Biology, Slovak Academy of Sciences, Dubravska cesta 21,
845 51 Bratislava, Slovakia
Gram-positive bacteria Streptomycetes are the main producers of bioactive natural products
including many antibiotics. The polyketides, which are synthesized by multifunctional
enzymes called polyketide synthase (PKS), belong to the most important classes of antibiotics.
We previously identified a type II polyketide synthase (PKS) gene cluster, aur1, in
Streptomyces aureofaciens CCM3239 with the highest similarity to angucycline polyketide
subgroup of PKS clusters. Deletion of two critical biosynthetic genes resulted in a lack of
antibiotic that was named auricin. However, its purification has been hampered by very
low yields. This cryptic phenotype has been recently described for several homologous
angucycline gene clusters, indicating their tight regulation. Sequence analysis of the
whole aur1 cluster revealed a huge number of regulatory genes, including six genes for
homologues of TetR family repressors, five genes for homologues of specific Streptomyces
Antibiotic Regulatory Proteins (SARP family), a single gene for homologue of AraC/
XylS-family regulators, a single genes for homologue of response regulators of bacterial
two-component signal transduction systems, and two genes for gama-butyrolactone
autoregulator-receptor system. Their partial characterization indicated that several of
them play a positive or negative role in auricin production in a cascade scheme.
Acknowledgements: This work was supported by the Slovak Research and Development
Agency under the contract No. APVV-0017-07.
XXII. Biochemistry Congress, Martin
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